1. Field of the Invention
This invention broadly relates to light emitting apparatus for curing photocurable dental material.
2. Description of the Related Art
Certain materials used in the field of dentistry such as adhesives, sealants and restorative materials are cured upon exposure to a source of light. Preferably, the materials cure when exposed to light having a wavelength in the visible range.
Photocurable dental materials are a convenience to the dentist because the curing process can be initiated when desired. For example, a dental filling may be placed in a tooth cavity in contact with a photocurable dental adhesive and manipulated as needed until the dentist is satisfied that the filling is oriented in its proper position. A source of light next to the tooth cavity is then activated to initiate polymerization of the adhesive and securely fix the filling in place.
There is limited room in the oral cavity for a curing light. Consequently, conventional light curing apparatus often include an elongated, slender light guide such as a bundle of optical fibers having a free end that can be positioned close to the photocurable material in order to direct light to the material from a light source located outside the oral cavity. In addition, such light guides are often detachable from the light source so that the light guide can be sterilized between uses among different patients.
Certain known light curing apparatus have a light source located within a housing of a handpiece, and a detachable light guide of the apparatus is made of a rigid, fused bundle of glass optical fibers having an outer end portion that extends at an angle to the major portion of the light guide. The angled end portion facilitates directing the light to certain areas in the oral cavity that might otherwise be difficult to reach.
The rigid, angled light guide of some curing apparatus may be swiveled about its major, longitudinal axis in order to further enhance the maneuvering of the directed light. In order to turn the light guide relative to the housing of such apparatus, the light guide is normally turned by grasping the light guide with one hand and gripping a handle of the housing with the opposite hand. However, such a procedure may be cumbersome, and increases the likelihood of contamination of the light guide, thereby also increasing the patient's risk of infection.
In some instances, it is difficult to manipulate the light guide so that the outer end of the light guide is directly adjacent the photocurable material. Removing the light guide from the oral cavity, turning the light guide and then reinserting the light guide in the oral cavity is somewhat time consuming and may have to be repeated in order to arrive at a proper rotational position of the light guide relative to the housing. Even after a desired rotational position of the light guide is obtained, the resultant orientation of the handle may cause discomfort to the dentist.